CN101466856B

CN101466856B - Copper alloy sheets for electrical/electronic part

Info

Publication number: CN101466856B
Application number: CN200780021714.9A
Authority: CN
Inventors: 有贺康博; 尾崎良一; 三轮洋介
Original assignee: Kobe Steel Ltd
Current assignee: Kobe Steel Ltd
Priority date: 2006-07-21
Filing date: 2007-06-20
Publication date: 2010-10-06
Anticipated expiration: 2027-06-20
Also published as: JP4117327B2; JP2008024994A; CN101466856A

Abstract

A shear plane ratio is reduced by a dislocation density in which a value obtained by dividing the half-value width of the intensity of diffraction of {311} plane in the surface of a Cu-Fe-P alloy sheet, by its peak height H, is 0.015 or more. In addition, a Cu-Fe-P alloy sheet with relatively small Fe content is provided with a texture in which a ratio (I (200)/I (220)) of intensity of diffraction of (I(200)) from the (200) plane in the sheet surface to intensity of diffraction of (I(220)) from the (220)plane, is 0.3 or less. In addition, a Cu-Fe-P alloy sheet with relatively small Fe content is provided with a texture in which the orientation distribution density of Brass orientation measured by the crystal orientation analysis method using an EBSP by an FE-SEM, is 25% or more; and an average grain size in the sheet is 6.0 [mu]m or less.

Description

Copper alloy sheets for electrical/electronic part

Technical field

The present invention relates to the Cu-Fe-P class copper alloy plate that high strength and drawing add the punch ram excellence in man-hour.

In addition, the present invention relates to that high strength and the intensity when eliminating thermal treatment such as strain annealing reduce less, the Cu-Fe-P class copper alloy plate of excellent heat resistance.

In addition, the present invention relates to high strength and for dealing with the Cu-Fe-P class copper alloy plate that packing crack and the problem peeled off improve the oxide film adaptation.Copper alloy plate of the present invention is optimum with the former material of lead frame as semiconductor device, except that semiconductor device with the lead frame, semiconductor device as other also is fit to use, and uses as various electrical/electronic parts such as mechanism elements such as electrical/electronic part materials such as printed circuit distributing board, switch part, bus-bar, terminal, terminal stud.But, in the following description,, be that the situation of lead frame is that the center describes to be used for semiconductor device as representational purposes example.

Background technology

As the semiconductor lead frame copper alloy plate, use the Cu-Fe-P class copper alloy that contains Fe and P usually.As these Cu-Fe-P class copper alloys, can illustration for example have: contain the copper alloy (C19210 alloy) of Fe:0.05～0.15%, P:0.025～0.04% and contain the copper alloy (CDA194 alloy) of Fe:2.1～2.6%, P:0.015～0.15%, Zn:0.05～0.20%.These Cu-Fe-P class copper alloys are because after in the copper parent phase intermetallic compounds such as Fe or Fe-P being separated out, especially the intensity of copper alloy, electroconductibility and excellent thermal conductivity are therefore, general as the international standard alloy.

In recent years, follow high capacity, miniaturization, the multifunction of the semiconductor device that is used for electronics, require to carry out long-pendingization of small cross-section of the lead frame that uses in the semiconductor device, and have higher intensity, electroconductibility, thermal conductivity.Therefore, the copper alloy that is used for the lead frame that these semiconductor devices use is also required higher high strength, thermal conductivity.

On the other hand, for the copper alloy plate of high strength, also require processibility to the lead frame of above-mentioned long-pendingization of small cross-section.Particularly, for copper alloy plate is processed to the lead frame drawing, copper alloy plate is required to have excellent punch ram.Even the purposes beyond this requirement lead frame also is identical in the purposes of punch ram worked copper alloy sheets.

In Cu-Fe-P class copper alloy plate, the present general following method of the method for raising punch ram: the trace of controlling Pb, Ca adds and makes the method for the chemical ingredientss such as compound dispersion that become the fracture starting point, reaches methods such as controlling crystal grain diameter.

But these methods or control itself is difficult, perhaps makes other deterioration in characteristics, in addition, therefore, has problems such as the manufacturing cost of involving rising.

Relative with it, motion has the tissue that is conceived to Cu-Fe-P class copper alloy plate and item that punch ram and bendability are improved.For example, in patent documentation 1, disclose and contain Fe:0.005～0.5wt%, P:0.005～0.2wt%, also contain a side or both sides among Zn:0.01～10wt%, the Sn:0.01～5wt% as required, rest part is by Cu and can not keep away the Cu-Fe-P class copper alloy plate that impurity constitutes.And in patent documentation 1, the integrated level of the crystal orientation by controlling this copper alloy plate makes punch ram raising (with reference to patent documentation 1).

More specifically, in patent documentation 1, utilize the control of this integrated level, along with the crystal grain diameter of copper alloy plate recrystallize and tissue becomes big, carry out to the plate surface { 200}, { the integrated ratio of 311} face increases, and when rolling, { the integrated ratio of 220} face increases.And, on feature, with 200}, the 311} face is relative, and increase to the plate surface { the integrated ratio of 200} face wishes to make the punch ram raising.More specifically, if in this plate surface from the X-ray diffraction intensity of 200} face is I[200], if from the X-ray diffraction intensity of 311} face is I[311], establish certainly the X-ray diffraction intensity of 220} face is I[220] time, satisfy [I[200]+I[311]]/I[220]＜0.4 formula.

In patent documentation 2, motion has following item: in order to improve punch ram, the ratio of X-ray diffraction intensity I (200) of (200) face of copper alloy plate and the X-ray diffraction intensity I (220) of (220) face: I (200)/I (220) is more than 0.5 below 10, perhaps, the orientation density in Cube orientation: D (Cube orientation) is 1～50, perhaps, the orientation density in the orientation density in Cube orientation: D (Cube orientation) and S orientation: the ratio of D (S orientation): D (Cube orientation)/D (S orientation) is 0.1～5 (with reference to patent documentation 2).

In addition, in patent documentation 3, motion has following item: in order to improve the bendability of Cu-Fe-P class copper alloy plate, make the X-ray diffraction intensity sum of the X-ray diffraction intensity of (200) face and (311) face and the ratio of the X-ray diffraction intensity of (220) face: [I (200)+I (311)]/I (220) is (with reference to a patent documentation 3) more than 0.4.

In addition, in patent documentation 4, motion has following item: in order to improve the bendability of Cu-Fe-P class copper alloy plate, make: I (200)/I (110) is (with reference to a patent documentation 4) below 1.5.

On the other hand, the Cu-Fe-P class copper alloy plate of high strength is required to have thermotolerance, even so that, intensity also takes place hardly reduce eliminating under the heat treated situation such as strain annealing.

Cu-Fe-P class copper alloy plate being carried out add man-hour,, make the multi-pin shape usually by drawing processing (punch ram processing) to lead frame etc.Recently, as mentioned above, for the miniaturization of electric, electronic component, thin-wall light-weighted corresponding, carrying out the thin-walled property and the multi-pinization of the copper alloy plate that uses as former material, therefore, on the processed goods after the above-mentioned drawing, there are easy residual strain stress and the inconsistent trend of hopper.Therefore, usually, the copper alloy plate of many hoppers shape that drawing is obtained is implemented thermal treatment (elimination strain annealing) and is removed strain.

, carry out such thermal treatment after, material is easily softening, the physical strength before can not maintenance heat handling.In addition,,, require at high temperature more, carry out in the short period of time, also have after the strong request thermal treatment at high temperature and can keep high-strength heat-resistant from the viewpoint that productivity improves from the manufacturing process aspect.

For such problem, still take following improvement strategy so far: make it contain trace additives such as alloying element such as Fe, P, Zn and other Sn, Mg, Ca, perhaps, adjust their addition etc.In addition, also carry out the crystallisate of copper alloy, the control of precipitate.But, be the control of such composition adjustment and crystallisate, precipitate, small-sized, lightweight that can not abundant corresponding copper alloy part and high-temperature capability characteristic etc., therefore, also motion has the technology such as tissue of control copper alloy.

For example, in patent documentation 5, being not Cu-Fe-P class copper alloy but the copper alloy that adds a spot of silver in the oxygen free copper is that former material uses, by control after rolling at last X-ray diffraction intensity than and roll at last before crystal grain diameter, realize the raising of intensity.Promptly, after hot rolling, carry out cold rolling and recrystallization annealing repeatedly, by control last in cold rolling degree of finish and the average crystal grain diameter after the last recrystallization annealing before cold rolling, and last annealing before cold rolling degree of finish, and control the X-ray diffraction intensity ratio after rolling at last and roll preceding crystal grain diameter at last, thereby realize high strength.But,, can not obtain the various high-level thermotolerance (with reference to patent documentation 5) of requirements such as above-mentioned lead frame even rolling, the annealing conditions of recommending in the document intactly is applicable to the Cu-Fe-P class copper alloy of the present invention as object.

Relative with it, also motion has the improved heat resistance technology in all Cu-Fe-P class copper alloys.For example, in patent documentation 6, motion has following item: by controlling substantial Fe content is 0.7% just to be the crystallisate of many Cu-Fe-P class copper alloys, the form self of precipitate when above, obtains high heat resistance.That is, motion has following item: the ratio that makes the X ray peak area X α of the X ray peak area X γ of the γ-Fe precipitate that contains in the tissue and α-Fe precipitate: X γ/X α is more than 0.05, obtains high heat resistance (with reference to patent documentation 6).

In addition, in patent documentation 7, motion has following item: obtain high heat resistance in order to set up jointly by control sets to knit, making substantial Fe content is 0.5% to be below 50% for many Cu-Fe-P class copper alloys with 500 ℃ of orientation density of carrying out 1 minute Cube orientation after the annealing just when above, also making median size is below the 30 μ m, obtains high heat resistance (with reference to patent documentation 7).

In addition, in patent documentation 2, be 2% just to be many Cu-Fe-P class copper alloys when above about substantial Fe content, disclose following item: be not to be purpose to improve thermotolerance, knit but set up jointly, improve the processibility of plate and to the plasticity of lead frame by control sets.This processibility is meant the fluctuation and the swing of the plate in cold rolling, the generation of swing, the bending in the drawing processing and the burr of the bar of inhomogeneous, the slitting shear machine of unrelieved stress, the orange peel of lead-in wire bending machining portion and crackle etc.In addition, set is organized as (200) face and the X-ray diffraction intensity ratio of (220) face and the orientation density in Cube orientation is controlled at proper range.

On the other hand, therefore the plastic wrapping of semiconducter device becomes main flow owing to utilize the packing economy and the mass production excellence of thermosetting resin sealing semiconductor chips.These packings are along with the requirement of the miniaturization of nearest electronic component, more and more thin-walled property.

In the encapsulation of these packings, usefulness Ag paste etc. perhaps, carry out soldering or Ag soldering via coating such as Au, Ag with semi-conductor chip and lead frame caking.And, carry out thereafter resin-sealed, carry out resin-sealed after, usually outer lead is electroplated the extraneous adornment of formation.

Packing crack that the problem of the maximum relevant with the reliability of these packings produces when being surperficial actual packaging and the problem of peeling off.It is as follows that the peeling off of packing produces: after the package semiconductor encapsulation, under the low situation of the adaptation of resin and backing plate (part of the bearing semiconductor chip of lead frame), the thermal stresses during thermal treatment after relying on produces.

In contrast, the packing crack is as follows: after the package semiconductor encapsulation, because mould resin utilizes atmosphere to carry out moisture absorption, therefore, after adding of surperficial actual packaging pine for moisture gasification, when package interior had the crack, water vapor was attached to release surface and waves effect as interior Hair Fixer.By pressing in this, perhaps produce protuberance on the packaging, perhaps resin internal pressure-resistant and produce the crack not.After producing the crack on the packing after the surperficial actual packaging, moisture and impurity are invaded and the corrosion chip, therefore, harm as semi-conductive function.In addition, behind the packing protuberance, become bad order, lose commodity value.In recent years, this packing crack and the problem peeled off are along with the slim progress of above-mentioned packing is more and more significant.

At this, packing crack and the problem peeled off cause by the adaptation of resin and backing plate is bad, and still, what the adaptation of resin and backing plate was caused maximum influence is the oxide film of lead frame mother metal.The lead frame mother metal is in order to make plate and to make lead frame, through various heating processes.Therefore, before plating such as Ag, be formed with the oxide film of tens of～hundreds of nm thickness on the surface of mother metal.On the backing plate surface, copper alloy and resin join via this oxide film, and therefore, peeling off of this oxide film and lead frame mother metal fully involves peeling off of resin and backing plate, and resin is reduced to the adaptation of lead frame mother metal.

Therefore, packing crack and the problem peeled off are relevant with the adaptation of this oxide film and lead frame mother metal.Therefore, require as follows to Cu-Fe-P class copper alloy plate:, be formed at the adaptation height of the oxide film on surface through after the various heating processes as the above-mentioned high strength of lead frame mother metal.

For such problem, motion does not have good countermeasure so far, and still, in patent documentation 8, motion has following item: the crystalline orientation by control copper alloy plate top layer, improve the oxide film adaptation.Promptly, in patent documentation 8, motion has following item: in the extremely surperficial crystalline orientation of the XRD membrane process evaluation that utilizes lead frame mother metal copper alloy, making (100) peak strength is below 0.04 with respect to the ratio of (111) peak strength, improves the oxide film adaptation.In addition,, in patent documentation 8, comprise all lead frame mother metal copper alloys, still, the content that illustrative in fact Cu-Fe-P class copper alloy is Fe is 2.4% just to be many Cu-Fe-P class copper alloys when above.

Patent documentation 1: Japan openly speciallys permit communique: 2000-328158 number (in full)

Patent documentation 2: Japan openly speciallys permit communique: 2002-339028 number (in full)

Patent documentation 3: Japan openly speciallys permit communique: 2000-328157 number (claims)

Patent documentation 4: Japan openly speciallys permit communique: 2006-63431 number (claims)

Patent documentation 5: Japan openly speciallys permit communique: 2003-96526 number (in full)

Patent documentation 6: Japan openly speciallys permit communique: 2004-91895 number (in full)

Patent documentation 7: Japan openly speciallys permit communique: 2005-139501 number (in full)

Patent documentation 8: Japan openly speciallys permit communique: 2001-244400 number (in full)

In above-mentioned

patent documentation

1 and 2, will be to { the 220} face and { the integrated ratio of 200} face increases, and makes the punch ram raising on plate surface.Increase by integrated ratio, can improve the punch ram of Cu-Fe-P class copper alloy plate really these certain surface.

But, long-pendingization of small cross-section of above-mentioned lead frame more and more advances, ((0.25mm → 0.15mm) also more and more littler, the requirement of punch ram raising that adds man-hour to the drawing of the Cu-Fe-P of high strength class copper alloy plate is stricter for 0.5mm → 0.3mm) and thickness of slab for wire widths.

Therefore, in the punch ram raising effect that the integrated ratio control of the tissue of above-mentioned

patent documentation

1 and 2 forms, do not satisfy the punch ram raising of this requirement.In addition, the copper alloy plate upper punch voltage lead wires that is utilizing above-mentioned

patent documentation

1 and 2 to carry out, utilize SEM to observe and measuring in the test conditions of punch ram of burr height of this moment, can not correctly evaluate the punch ram of above-mentioned requirements of the Cu-Fe-P class copper alloy plate of high strength.

In addition, the technology that rises to these patent documentations 6,7 of purpose with Cu-Fe-P class copper alloy plate stable on heating, and or the technology of the different patent documentation 2 of purpose in, do not reach and ensure the high-level thermotolerance of expecting among the present invention.

That is, the substantial Fe content of the Cu-Fe-P class copper alloy of these patent documentations is minimum also to be to surpass 0.5%, and in this, perhaps the technology of these patent documentations improves really effectively the thermotolerance of the many Cu-Fe-P class copper alloys of Fe content.

But Fe content surpasses at 0.5% o'clock, produces to reduce electric conductivity and this other problem of Ag plating property.Relative with it, in the time of must increasing the amount of separating out of above-mentioned precipitation particles for example for electric conductivity force to be increased, cause growth, thickization of precipitation particles on the contrary, there are intensity and stable on heating problem.In other words, in the technology of these patent documentations, can not have the high strength and the thermotolerance of Cu-Fe-P class copper alloy requirement concurrently.

Therefore, even the technology utilization of these patent documentations is reduced to composition below 0.5% in fact with the content of Fe, and intactly be applicable to the Cu-Fe-P class copper alloy of high strength, can not obtain the high-level thermotolerance that above-mentioned lead frame etc. requires.

In addition, in the technology of patent documentation 8, do not reach and ensure the high-level thermotolerance of expecting among the present invention.

That is, the substantial Fe content of the Cu-Fe-P class copper alloy in the patent documentation 8 as mentioned above, even minimum also to surpass 2.4 quality % many.In this, perhaps the technology of patent documentation 8 improves really effectively the oxide film adaptation of the many Cu-Fe-P class copper alloys of Fe content.In fact, in patent documentation 8, Fe content is that the oxide film adaptation of the Cu-Fe-P class copper alloy of 2.41% embodiment 1 is brought up to 633K (360 ℃) in the critical temperature of peeling off of oxide film.

But Fe content surpasses 2.4 quality % for a long time, produces following other problem: not only material behavior such as electric conductivity significantly reduces, and productivity such as castibility also significantly reduces.In fact, in patent documentation 8, just for than higher, just be low when electric conductivity is 63%LACS when the tensile strength of the Cu-Fe-P class copper alloy of the foregoing description 1 is 530MPa.

In contrast, increase reluctantly in order to make electric conductivity, for example, the amount of separating out of above-mentioned precipitation particles is increased after, cause growth, thickization of precipitation particles on the contrary, exist and reduce intensity and stable on heating problem.In other words, in the technology of patent documentation 8, can not have the high strength and the oxide film adaptation of Cu-Fe-P class copper alloy requirement concurrently.

Therefore,, and intactly be applicable to the Cu-Fe-P class copper alloy of high strength, can not obtain the oxide film adaptation that above-mentioned lead frame etc. requires even these patent documentation 8 technology utilizations are reduced to composition below 0.5% in fact with the content of Fe.

Summary of the invention

The present invention develops for solving above-mentioned problem, and its purpose is to provide a kind of Cu-Fe-P class copper alloy plate, and it has high strength and excellent punch ram concurrently.

In addition, the present invention develops for solving above-mentioned problem, and its purpose is to provide a kind of Cu-Fe-P class copper alloy plate, and it utilizes content with Fe to be reduced to composition 0.5% below in fact, also has the thermotolerance of high strength and excellence concurrently.

In addition, the present invention develops for solving above-mentioned problem, and its purpose is to provide a kind of Cu-Fe-P class copper alloy plate, and it utilizes content with Fe to be reduced to composition 0.5% below in fact, also has the oxide film adaptation of high strength and excellence concurrently.

In order to realize described purpose, the central topic of the copper alloy sheets for electrical/electronic part of the present invention of punch ram excellence is in quality %, the copper alloy plate that contains Fe:0.01～0.50%, P:0.01～0.15% respectively, wherein, the plate surface from { half breadth of the X-ray diffraction intensity peak value of 311} face is more than 0.015 divided by the value of its peak height gained.

Copper alloy plate of the present invention also can contain Sn, Zn respectively, in order to realize high strength, also contains the Sn in quality % 0.005～5.0%, perhaps for soldering and tinned heat-resisting separability improvement, also contains the Zn in quality % 0.005～3.0%.

Copper alloy plate of the present invention is as high-intensity roughly standard, and preferred tensile strength is more than the 500MPa, and hardness is more than the 150Hv.In addition, electric conductivity is relevant with the intensity of plate, and said high conductivity is meant that electric conductivity is than higher in high-intensity ratio among the present invention.

Copper alloy plate of the present invention also can also contain among quality % Mn, Mg, the Ca one or two or more kinds, add up to 0.0001～1.0%.

Copper alloy plate of the present invention also can also contain among quality % Zr, Ag, Cr, Cd, Be, Ti, Co, Ni, Au, the Pt one or two or more kinds, add up to 0.001～1.0%.

Copper alloy plate of the present invention also can also contain respectively among quality % Mn, Mg, the Ca one or two or more kinds, add up to 0.0001～1.0%; Contain among Zr, Ag, Cr, Cd, Be, Ti, Co, Ni, Au, the Pt one or two or more kinds, add up to 0.001～1.0%, and the total content that makes these elements that contain is below 1.0%.

Copper alloy plate of the present invention also preferably makes the content of Hf, Th, Li, Na, K, Sr, Pd, W, S, Si, C, Nb, Al, V, Y, Mo, Pb, In, Ga, Ge, As, Sb, Bi, Te, B, norium count below the 0.1 quality % with all totals of these elements.

In addition, for the central topic of the copper alloy sheets for electrical/electronic part of the present invention of realizing described purpose for containing copper alloy plate respectively in quality % Fe:0.01～0.50%, P:0.01～0.15%, wherein, make the plate surface from the X-ray diffraction intensity I (200) of (200) face with from the ratio of the X-ray diffraction intensity I (220) of (220) face: I (200)/I (220) is below 0.3.

Copper alloy plate of the present invention is in order to realize high strength, also contains to count 0.005～5.0% Sn with quality %, perhaps improves for soldering and tinned heat-resisting separability, also contains to count 0.005～3.0% Zn with quality %.

In addition, for the central topic of the copper alloy sheets for electrical/electronic part of the present invention of realizing described purpose for containing respectively in quality % Fe:0.01～0.50%, the copper alloy plate of P:0.01～0.15%, wherein, regard as under the crystalline situation that belongs to same crystal plane with interior crystallization for ± 15 ° in crystalline azimuth difference adjacent one another are, have according to the crystal orientation method of analysis of the rear electron diffraction at random that uses electric field radioactive scanning electronic microscope FE-SEM as EBSP, the orientation distribution density in the Brass orientation of measuring is the set tissue more than 25%, and making average crystal grain diameter is below the 6.0 μ m.

Copper alloy plate of the present invention also contains the Sn in quality % 0.005～5.0% in order to realize high strength, perhaps for soldering and tinned heat-resisting separability improvement, also contains the Zn in quality % 0.005～3.0%.

In the present invention, same with described

patent documentation

1 and 2 etc., as seen stipulate the X-ray diffraction intensity by specific crystal orientation on plate surface, and control sets is set up and is knitted jointly.But

patent documentation

1 and 2 comes down to regulation crystalline orientation, in order to reduce (reduction) burr height when the copper alloy plate upper punch voltage lead wires, must improve the integrated ratio of (220) face.

But originally, in having the copper alloy of arbitrary orientation, the integrated ratio that only increases particular orientation has big limit.This with must select

patent documentation

1 and 2 etc. stipulate among 220} face and the present invention { crystal orientation such as 311} face is identical.Here it is in the punch ram raising effect of the integrated ratio control of described

patent documentation

1 and 2 such tissues, can not satisfy the reason of the punch ram of Cu-Fe-P class copper alloy plate requirement.

Relative with it, in the present invention, not the integrated ratio that control has such particular orientation (crystal orientation) now, but the dislocation desity of control Cu-Fe-P class copper alloy plate tissue.That is, improve the dislocation desity of Cu-Fe-P class copper alloy plate tissue, can improve punch ram.Personnel's the penetrating and correct judgement according to the present invention, this dislocation desity can be controlled its import volume according to the kicker spare of Cu-Fe-P class copper alloy plate, and strengthens the punch ram raising effect of this dislocation desity control.

But,, therefore, that dislocation desity direct viewing or the quantification that imports Cu-Fe-P class copper alloy plate tissue is very difficult because this dislocation desity is very small problem.But, personnel's the penetrating and correct judgement according to the present invention, this dislocation desity of importing Cu-Fe-P class copper alloy plate tissue and the half breadth of X-ray diffraction intensity peak value or half breadth are closely related divided by the value of X-ray diffraction intensity peak height gained.In this case, even any X-ray diffraction intensity peak value is relevant with this dislocation desity too.But, the plate surface of stipulating among the present invention from { the X-ray diffraction intensity peak value of 311} face is compared with the X-ray diffraction intensity peak value from other faces, the X-ray diffraction intensity peak value that should remove half breadth is big (height) not too, and half breadth also at that, therefore, the half breadth of X-ray diffraction intensity peak value is divided by the value reliability height of height gained.Thereby, in the present invention, utilize the plate surface from the X-ray diffraction intensity peak value of 311} face, though with this dislocation desity to be very correct indirectly and to have form regulation, the quantification of reproducibility.

Like this, in the present invention, utilize with the closely-related plate of dislocation desity amount surface from { half breadth of the X-ray diffraction intensity peak value of 311} face is stipulated this dislocation desity amount, can improve punch ram, and satisfies the punch ram of Cu-Fe-P class copper alloy plate requirement.And can improve preferred tensile strength is that 500MPa is above, hardness is the punch ram of the above high-intensity Cu-Fe-P class copper alloy plate of 150Hv.

In the present invention, make above-mentioned X-ray diffraction intensity ratio: I (200)/I (220) is that the reason below 0.3 is: the prosperity in control Cube orientation, and the prosperity of the specific crystal orientation beyond the Reinforced Cu be orientation strengthens anisotropy, thereby obtains excellent thermotolerance.In addition, reason is to utilize content with Fe to be reduced to composition 0.5% below, the thermotolerance of also can get both high strength and excellence in fact.

In contrast, making I (200)/I (220) and the present invention with identical X-ray diffraction intensity than the described patent documentation 2 of regulation is more than 0.5 below 10 mutually on the contrary.This be because: opposite in order to improve described processibility in patent documentation 2 with the present invention, make the prosperity in Cube orientation, and suppress the flourishing grow of the specific crystal orientation beyond the Cube orientation, and must suppress anisotropy.Therefore, in the content with Fe was reduced to composition below 0.5% in fact, high strength and excellent thermotolerance can not get both.

Under the situation of common copper alloy plate, main form Cube orientation shown below be called Goss orientation, Brass orientation (below, also claim the B orientation), the set tissue in Copper orientation (below, also claim the Cu orientation), S orientation etc., and have corresponding their crystal plane.

Under the situation that is formed on identical crystal system of these set tissues also according to processing, heat treating method and difference.Under the situation of the set tissue that rolls the sheet material that forms, to roll face and roll direction indication, the face that rolls is with (ABC) expression, rolls direction with＜DEF〉expression.Based on such expression, each orientation references is following to be stated.

The Cube orientation 001}＜100 〉

The Goss orientation 011}＜100 〉

The Rotated-Goss orientation 011}＜011 〉

Brass orientation (B orientation) 011}＜211 〉

Copper orientation (Cu orientation) 112}＜111 〉

(or the D orientation 4411}＜11118 〉)

The S orientation 123}＜634 〉

The B/G orientation 011}＜511 〉

The B/S orientation 168}＜211 〉

The P orientation 011}＜111 〉

At this, the fiber collection tissue that the B orientation～Cu orientation～S orientation changes continuously with each side's interdigit (β-fiber) exist.

The set of common copper alloy plate is organized as mentioned above, be made of considerable steric factor, but when these component ratios changed, the plastic anisotropy of sheet material changes, and characteristic variations such as processibility and plasticity.

Described patent documentation 8 makes especially that { the 100} peak strength is with respect to { ratio of 111} peak strength is below 0.04, can improve the oxide film adaptation in this set tissue.But, like this, with respect to Copper orientation (Cu orientation), even the orientation distribution density in Cube orientation and Goss orientation is increased, especially be less than in the copper alloy plate that the Cu-Fe-P class below 0.5% forms having the content that makes Fe of the present invention as object, can not high strength, and can not improve the adaptation of oxide film.Therefore, in the copper alloy plate that the poor Cu-Fe-P class with this Fe is formed, high strength and excellent thermotolerance can not get both.

In contrast, in the present invention,, make the set tissue in same orientation as much as possible with the orientation distribution density increase (raising) of Brass orientation (110 face).Thus, in the copper alloy plate that the poor Cu-Fe-P class with this Fe is formed, high strength and excellent thermotolerance can get both.

That is, in the copper alloy plate that the poor Cu-Fe-P class with this Fe is formed, in above-mentioned set tissue, especially the orientation distribution density in Brass orientation (B orientation) is big to the adaptation influence of oxide film.The orientation distribution density in this B orientation is big more, rolls to gather to organize all the more to reach, and intensity is high more, and improves the adaptation of oxide film more.

Copper alloy plate of the present invention is to use in the semiconductor lead frame purposes applicable to various electrical/electronic part usefulness particularly preferably in semiconductor device.

Description of drawings

Fig. 1 is the synoptic diagram of the half breadth of expression X-ray diffraction intensity peak value.

Fig. 2 is the explanatory view of the measuring method of expression shear surface rate.

Nomenclature

1 copper alloy plate

2 punching hole

3 shear the position

Embodiment

(1)

Below, the meaning and the embodiment of each prerequisite characteristic, Cu-Fe-P class copper alloy plate of the present invention of necessity such as use to specifically describe to being used for satisfying as semiconductor lead frame.

(half breadth)

In the present invention, for the punch ram that improves punch ram and meet the demands, have Cu-Fe-P class copper alloy plate surface from { half breadth of the X-ray diffraction intensity peak value of 311} face is the dislocation desity more than a certain amount of 0.015 or more divided by the value of its peak height gained.Thus, more specifically, can make tensile strength is that 500MPa is above, hardness is the punch ram raising of the above high-intensity Cu-Fe-P class copper alloy plate of 150Hv.

During divided by the value less than 0.015 of its peak height gained, the dislocation desity that imports plate tails off at the half breadth of this X-ray diffraction intensity peak value.So far, existing dislocation desity is few, does not have big gap with Cu-Fe-P class copper alloy plate, punch ram reduction or do not improve.

As everyone knows, as schematically shown in Figure 1, this half breadth is as giving a definition: the longitudinal axis: X-ray diffraction intensity, transverse axis: define as half the width (β) of X-ray diffraction intensity peak value of position (height H/2) with the X-ray diffraction intensity peak value (height H) of angle (2 θ) expression.By the way, this half breadth is generally the crystallinity of metallic surface and amorphism, crystallite granularity, lattice deformability differentiation and quantification and uses.In contrast, in the present invention, as mentioned above, utilize with the closely-related plate of this dislocation desity surface from { the half breadth β of the X-ray diffraction intensity peak value of 311} face is divided by the value of its peak height H gained, and regulation can not direct viewing or the dislocation desity of quantification.In addition, as the X-ray diffraction intensity peak value of Cu-Fe-P class copper alloy plate, other { half breadth (β) of the X-ray diffraction intensity peak value of 220} face and peak height (H) maximum thereof certainly.But, during the height of X-ray diffraction intensity peak value big (height), its peak height of removing half breadth also becomes greatly, becomes too small as the half breadth of X-ray diffraction intensity peak value divided by the value of its peak height gained, and the error that is worth self becomes big, thereby lacks reproducibility.Therefore, in the present invention, adopt certainly { the X-ray diffraction intensity peak value of 311} face of the half breadth of X-ray diffraction intensity peak value divided by the value big (the peak height change is big, and it is big that half breadth just correspondingly becomes) of its peak height gained.

Therefore, among the present invention, from start to finish will be to the importing state of the dislocation desity of plate as problem, not X-ray diffraction intensity peak value with the specific crystal plane on above-mentioned

patent documentation

1 and 2 such plate surfaces, the integrated ratio of control tissue, the crystal grain diameter on plate surface or roll the set tissue.In other words, in the X-ray diffraction intensity peak value of the specific crystal plane on these plate surfaces, perhaps, at the crystal grain diameter on integrated ratio, the plate surface of tissue or roll in the control of set tissue etc., can not stipulate to control importing state to the dislocation desity of plate.

(importing of dislocation desity)

For import Cu-Fe-P class copper alloy plate surface from { half breadth of the X-ray diffraction intensity peak value of 311} face is a dislocation desity 0.015 or more divided by the value of its peak height gained, and is as described below, strengthens the importing dependent variable at last cold rolling.That is, select to use or preferably combination makes with the following method: the roller diameter in will be last cold rolling makes the roll of the minor diameter of not enough Φ 80mm, and the draft that perhaps makes each mill train is more than 20%, perhaps make roll length (roll width) for 500mm with first-class.

(shear surface rate)

As mentioned above,

patent documentation

1 and 2 carry out at copper alloy plate upper punch voltage lead wires and measure in the test conditions of punch ram of burr height of this moment, can not correctly evaluate the punch ram of this requirement.

Therefore, in the present invention, the shear surface rate (shear surface ratio) in the lead-in wire cross section of the lead-in wire punching press by utilizing the copper alloy plate that the mimic punch ram is provided with is more correctly evaluated punch ram.As long as this shear surface rate is below 75%, punch ram can be assessed as well.Certainly, also can attach the mensuration of above-mentioned burr height, with the punch ram evaluation that confirms that this shear surface rate gives at this.

At this moment, for the shear surface rate evaluation in the test of punch press stampability is kept reproducibility, the test conditions that as far as possible guarantees reproducibility is stipulated particularly.Promptly, as shown in Figure 2, the punch ram test utilizes punching press punch press (die clearance: 5%), use Japan work oil system G-6316 lubricating oil, according to length direction vertically towards the mode of the rolling direction of copper alloy plate 1, the lead-in wire of punching press width 1mm * length 10mm.

Thus, (dotting cutting part) cut at the center of punching hole 2 along its length, the cut surface of punching hole 2 is observed from the direction of arrow 4,, obtain with the image parsing according to surface picture with the microscopical cut surface of optics.Shearing rate is the area ratio (area of the area/cut surface of shear surface) of the shear surface in the cut surface, the area of cut surface is the thickness of slab 0.15mm * mensuration width 0.5mm of copper alloy plate, and the area of shear surface is for measuring the area of the shear surface in the width 0.5mm scope.3 holes of each sample punching press, in each hole, each measures 3 positions (adding up to 9 positions), obtains its mean value.

(one-tenth of copper alloy plate is grouped into)

In the present invention, use etc. as semiconductor lead frame, with tensile strength be more than the 500MPa, hardness is high strength more than the 150Hv and above-mentioned punch ram is realized in the lump.Therefore, as Cu-Fe-P class copper alloy plate, it basic composition is: in quality %, the content of Fe is that the content of 0.01～0.50% scope, above-mentioned P is 0.01～0.15% scope, and rest part is by Cu and can not keep away impurity and constitute.

With respect to this essentially consist, also can be for further containing a kind of or two kinds mode among Zn, the Sn with following ranges.In addition, other selectivity are added elements and impurity element and are also allowed in the scope that does not hinder these characteristics and contain.In addition, the expression % of the content of alloying element and impurity element all is the meaning of quality %.

(Fe)

Fe separates out as Fe or Fe base intermetallic compound, is intensity and the stable on heating principal element that improves copper alloy.Fe contain quantity not sufficient 0.01% time, according to creating conditions, the growing amount of above-mentioned precipitation particles is few, though satisfy the raising of electric conductivity, is helpless to that intensity improves and undercapacity.On the other hand, when the content of Fe surpasses 0.50%, electric conductivity and plating Ag reduction.In the time the amount of separating out of above-mentioned precipitation particles must being increased, cause growth, thickization of precipitation particles on the contrary in order to force to increase electric conductivity.Therefore, intensity and punch ram reduction.Thereby the content of Fe is 0.01～0.50% scope.

(P)

P forms compound with Fe, for making the principal element of copper alloy high strength except that having desoxydatoin.P contain quantity not sufficient 0.01% time, according to creating conditions because separating out of compound is insufficient, the therefore intensity that can not obtain to require.On the other hand, when the content of P surpassed 0.15%, not only electric conductivity reduced, and hot workability and punch ram reduction.Thereby the content of P is 0.01～0.15% scope.

(Zn)

Zn improves the soldering of the copper alloy of necessity such as lead frame and the heat-resisting separability of plating Sn.Under the situation that contains quantity not sufficient 0.005% of Zn, can not obtain desired effects.On the other hand, when surpassing 3.0%, not only soldering soakage reduces, and electric conductivity also reduces greatly.Therefore, the balance (consideration balance) of electric conductivity that the content that makes the Zn that its selectivity contains requires according to purposes and the heat-resisting separability of soldering and plating Sn is selected in 0.005～3.0% scope.

(Sn)

Sn helps the intensity of copper alloy to improve.Under the situation that contains quantity not sufficient 0.001% of Sn, be helpless to high strength.On the other hand, when the content of Sn for a long time, its effect is saturated, causes electric conductivity to reduce on the contrary.Therefore, make the intensity (hardness) that content that its selectivity contains Sn sometimes requires according to purposes and the balance (consideration balance) of electric conductivity, selection in 0.001～5.0% the scope and it is contained.

(Mn, Mg, Ca amount)

Mn, Mg, Ca help the raising of the hot workability of copper alloy, therefore, under the situation that these effects need, can selectively contain.The content of one or two or more kinds adds up under the situation of less than 0.0001% in Mn, Mg, Ca, can not obtain desired effects.On the other hand, its content adds up to and surpasses at 1.0% o'clock, generates thick crystallisate and oxide compound, not only reduces intensity and thermotolerance, and electric conductivity also sharply descends.Therefore, the content of these elements selectively contains it in total amount in 0.0001～1.0% scope.

(Zr, Ag, Cr, Cd, Be, Ti, Co, Ni, Au, Pt amount)

These compositions have the effect of the intensity that improves copper alloy, therefore, under the situation that these effects need, can selectively contain.The content of one or two or more kinds adds up under the situation of less than 0.001% in these compositions, can not obtain desired effects.On the other hand, its content adds up to and surpasses at 1.0% o'clock, generates thick crystallisate and oxide compound, not only reduces intensity and thermotolerance, and also sharply decline of electric conductivity, and is not preferred.Therefore, the content of these elements is aggregated in 0.001～1.0% the scope it is selectively contained.In addition, under the situation that these compositions and above-mentioned Mn, Mg, Ca are contained jointly, the total content of the element that these contain is below 1.0%.

(Hf, Th, Li, Na, K, Sr, Pd, W, S, Si, C, Nb, Al, V, Y, Mo, Pb, In, Ga, Ge, As, Sb, Bi, Te, B, norium amount)

These compositions are impurity element, surpass under 0.1% the situation in the total of the content of these elements, generate thick crystallisate and oxide compound and make intensity and thermotolerance reduction.Therefore, the content of these elements total is preferably below 0.1%.

(creating conditions)

Below, to be used to make the copper alloy plate tissue become the invention described above regulation tissue, preferably create conditions and describe.Copper alloy plate of the present invention except that the tissue that is used to make the present invention's regulation that imports above-mentioned dislocation desity, the preferred condition such as last cold rolling condition, do not need the earth to change common manufacturing process self, can utilize the operation manufacturing identical with ordinary method.

That is, at first, cast being adjusted into the copper alloy solution that above-mentioned preferred one-tenth is grouped into.And, ingot casting carried out building up by welding after, heat or the thermal treatment that homogenizes, carry out hot rolling afterwards, the plate after the hot rolling is carried out water-cooled.

Thereafter, the once cold rolling of rolling in being called as, carries out that essence (at last) is cold rolling, low-temperature annealing (annealing at last, smart annealing) after cleaning again at annealing, makes the copper alloy plate of finished product thickness of slab.Also can carry out these annealing and cold rolling repeatedly.For example, be used under the situation of semi-conductor such as lead frame with the copper alloy plate of material, the finished product thickness of slab is 0.1～0.4mm degree.

In addition, also can before once cold rolling, carry out the solution treatment of copper alloy plate and the quench treatment of water-cooled.At this moment, solid solution temperature is from for example selecting in 750～1000 ℃ the scope.

(cold rolling at last)

For with Cu-Fe-P class copper alloy plate surface from { half breadth of the X-ray diffraction intensity peak value of 311} face is that dislocation desity 0.015 or more imports divided by the value of its peak height gained, and is as described below, needs to strengthen the importing dependent variable at last cold rolling.Promptly, select use or preferably combination to make with the following method: the roll that the roller diameter at last cold rolling is made the minor diameter of not enough Φ 80mm, perhaps making the minimum draft (cold rolling rate, working modulus) of each mill train is more than 20%, and perhaps making roll length (roll width) is that 500mm is with first-class.

Roller diameter in the end cold rolling is too small, the minimum draft of each mill train is too small, when roll length is too short, the insufficient possibility of dislocation desity that imports Cu-Fe-P class copper alloy plate is big.Therefore, the plate surface from { half breadth of the X-ray diffraction intensity peak value of 311} face is divided by the value less than 0.015 of its peak height gained, and existing dislocation desity is few, does not have big gap with Cu-Fe-P class copper alloy plate, punch ram reduction or do not improve.

Last cold rolling mill train number is avoided very few and too much mill train number, preferably carries out with 3～4 times common mill train numbers.In addition, the draft of each mill train need not to surpass 50%, and each draft of each mill train is considered the minimum draft of former thickness of slab, the final thickness of slab after cold rolling, mill train number, above-mentioned each mill train and this maximum depression rate and determined.

(annealing at last)

In the present invention, in the end cold rolling after, preferably carry out with cryogenic last annealing.This last annealing conditions is preferably with 100～400 ℃, 0.2～300 minute cold condition.In the manufacture method of the common copper alloy plate that is used for lead frame, except that the annealing that is used to reduce intensity, be used to eliminate stress (350 ℃ * 20 seconds degree), in the end cold rolling after, do not anneal at last.But, in the present invention,, in addition,, can suppress this intensity and reduce by last annealed low temperatureization according to above-mentioned cold rolling condition.And, by annealing at last, improve punch ram with low temperature.

Be lower than 100 ℃ temperature and 0.2 minute time conditions of annealing time less than or do not carry out under this stress relief annealed condition in annealing temperature, the tissue of copper alloy plate, characteristic are big from the last almost indeclinable possibility of state after cold rolling.On the contrary, surpass time that 400 ℃ temperature and annealing time surpass 300 minutes when annealing, produce recrystallize with annealing temperature, excessively produce the arrangement again of dislocation and recover phenomenon, precipitate is thickization also, and therefore, the possibility that punch ram and intensity reduce is big.

(embodiment 1)

Below, embodiments of the invention are described.The roller diameter during change is at last cold rolling and the minimum draft of each mill train are made the { copper alloy plate of the half breadth (dislocation desity) of the X-ray diffraction intensity peak value of 311} face certainly with various plates surface.And, characteristics such as the tensile strength of these each copper alloy plates, hardness, electric conductivity, shear surface rate are evaluated.These results of table 1 expression.

[table 1]

* in the expression of the content of each element ,-expression detects below the boundary.

Particularly, the copper alloy that each chemical ingredients shown in the table 1 is formed after the melting, does not utilize semicontinuous casting method caststeel ingot respectively in being in the mood for stove, obtain the ingot casting of thickness 70mm * width 200mm * length 500mm.With each ingot casting carry out building up by welding and the heating after, carry out hot rolling with 950 ℃ temperature, make the plate of thickness 16mm, from the temperature more than 750 ℃ at quenching-in water.Then, remove descaling after, carry out once cold rolling (in roll).After this plate carried out building up by welding, carry out the limit and enter the process annealing limit and carry out cold rolling cold rolling at last of 4 mill traines, then, anneal at last, obtain the copper alloy plate of the thickness 0.15mm of corresponding lead frame thin plateization with 350 ℃, 20 seconds cold condition.

Table 1 is represented the last cold rolling roller diameter (mm) and the minimum draft (%) of each mill train respectively.In addition, in the end cold rolling in, use the roll of all identical roller diameter of four mill traines.In addition, even change roller diameter, each roll length also one is decided to be 500mm.

In addition, it all is Cu that the rest part of each copper alloy shown in the table 1 except that above-mentioned amount of element formed, as other impurity element, the content of Hf, Th, Li, Na, K, Sr, Pd, W, S, Si, C, Nb, Al, V, Y, Mo, Pb, In, Ga, Ge, As, Sb, Bi, Te, B, norium comprises the element that souvenir carries, in all totals of these elements, be below the 0.1 quality %.

In addition, in containing Mn, Mg, Ca under the situation of one or two or more kinds, making the total amount is the scope of 0.0001～1.0 quality %, in containing Zr, Ag, Cr, Cd, Be, Ti, Co, Ni, Au, Pt under the situation of one or two or more kinds, making the total amount is the scope of 0.001～1.0 quality %, in addition, all total amounts of these elements also are below the 1.0 quality %.

For the copper alloy plate that obtains like this, each example all cuts sample from copper alloy plate, and characteristics such as the dislocation desity of each sample (set tissue), tensile strength, hardness, electric conductivity, thermotolerance are evaluated.Table 1 is represented these results respectively.

(mensuration of half breadth)

To the copper alloy plate sample, utilize common X-ray diffraction method, on target, use Co, under the condition of tube voltage 50kV, tube current 200mA, 2 °/min of sweep velocity, 0.02 ° of width of sampling, 30 °～115 ° of measurement ranges (2 θ), with リガ Network system X-ray diffraction device, obtain X-ray diffraction pattern.Thus, utilize above-mentioned method to obtain the { half breadth of the X-ray diffraction intensity peak value of 311} face certainly on plate surface.

Measure at two positions, half breadth is their mean value.

(measurement of hardness)

The measurement of hardness of copper alloy plate sample is as follows: utilize micro Vickers, add the load of 0.5kg, carry out at three positions, hardness is their mean value.

(electric conductivity measuring)

The electric conductivity measuring of copper alloy plate sample is as follows: utilize milling that the rectangular test film of width 10mm * length 300mm is processed, utilize double bridge formula resistance measurement device to measure resistance, utilize the average cross-section method to calculate.

(shear surface rate mensuration)

Utilize above-mentioned test conditions, measure the shear surface rate (shear surface ratio) of copper alloy plate sample.According to carrying out image with the surface picture of the microscopical cut surface of optics when resolving, even also measure with reference to the burr height of the maximum of the lead-in wire that is provided with.

Show that by table 1 copper alloy in the present invention forms is to make in the also preferred condition of the manufacture method such as minimum draft of the in the end cold rolling roller diameter of example 1～14 and each mill train.Therefore, example 1～14 have the plate surface from { half breadth of the X-ray diffraction intensity peak value of 311} face is the dislocation desity more than a certain amount of 0.015 or more divided by the value of its peak height gained.

This result is, example 1～14 in tensile strength is more than the 500MPa, hardness is in the high-intensity ratio more than the 150Hv, and for than high electrical conductivity, in addition, the shear surface rate is below 75%, and punch ram is also excellent.

Relative with it, though comparative example 15～17 is formed interior copper alloy for the present invention,, the at last cold rolling roller diameter and the minimum draft of each mill train are too small.Therefore, comparative example 15～17 its plate surfaces from { half breadth of the X-ray diffraction intensity peak value of 311} face is divided by the value less than 0.015 of its peak height gained, and dislocation desity is low excessively.This result is, in the low ratio of strength criterion, the shear surface rate is more than 78%, and punch ram is significantly inferior.

The content of its Fe of copper alloy of comparative example 18 is 0.006% o'clock, is lower than lower limit 0.01%.On the other hand, make in the also preferred condition of the manufacture method such as minimum draft of in the end cold rolling roller diameter and each mill train.Therefore, though have the plate surface from the half breadth of the X-ray diffraction intensity peak value of 311} face is a dislocation desity more than 0.015 divided by the value of its peak height gained,, in the low ratio of intensity and hardness, shear surface rate height, punch ram is poor, can't realize high strength.

The content of its Fe of copper alloy of comparative example 19 is 0.55% o'clock, exceeds the upper limit 5.0%, goes beyond the scope, but makes in the preferred condition of manufacture method such as in the end cold rolling.Therefore, though have the plate surface from the half breadth of the X-ray diffraction intensity peak value of 311} face is a dislocation desity more than 0.015 divided by the value of its peak height gained,, shear surface rate height, punch ram is poor, electric conductivity is significantly low.

The content of its P of copper alloy of comparative example 20 is 0.007% o'clock, is lower than lower limit 0.01%, but makes in the preferred condition of manufacture method such as in the end cold rolling.Therefore, though have the plate surface from the half breadth of the X-ray diffraction intensity peak value of 311} face is a dislocation desity more than 0.015 divided by the value of its peak height gained,, in the low ratio of intensity and hardness, shear surface rate height, punch ram is inferior, can't realize high strength.

The content of its P of copper alloy of comparative example 21 is 0.16% o'clock, exceeds the upper limit 0.15%, therefore, in hot rolling, cracks in the plate end.But, make in the preferred condition of manufacture method such as in the end cold rolling.Therefore, though have the plate surface from the half breadth of the X-ray diffraction intensity peak value of 311} face is a dislocation desity more than 0.015 divided by the value of its peak height gained,, shear surface rate height, punch ram is poor, in addition, electric conductivity is significantly low.

(burr height)

Foregoing invention example 1～14 is in above-mentioned punch ram test, and observed burr height (maximum) all is below the 5 μ m.In addition, the burr height in above-mentioned comparative example 15～17 its punch ram tests also all is below the 5 μ m, no less than example.On the other hand, the burr height in above-mentioned comparative example 18～21 its punch ram tests all surpasses 6 μ m, and is poorer than the foregoing invention example.

Therefore, the evaluation of the burr height in the punch ram test can be in the use in the comparison, identification of (example 1～14 and comparative example 18～21) each other of extremely different each example of punch ram.But in example 1～14 and the comparative example 15～17, error is not too obvious on the burr height as can be known, the identification that can not very deny.That is, as can be known among the present invention as the standard of problem promptly: along with corresponding wire widths and the thickness of slab that diminishes of long-pendingization of small cross-section of above-mentioned lead frame, add in the punch ram evaluation in man-hour insufficient in the drawing of the Cu-Fe-P of high strength class copper alloy plate.

Can confirm following meaning by above result: make on its high strength, the one-tenth that is used on the punch ram also excellent copper alloy plate of the present invention is grouped into, the plate surface from { half breadth of the X-ray diffraction intensity peak value of 311} face is divided by the critical meaning of the value of its peak height gained and be used to obtain the meaning of preferably creating conditions of this tissue.

(2)

(X-ray diffraction intensity ratio)

X-ray diffraction intensity of the present invention is such as measuring down: the Cube orientation with common X-ray diffraction method assay plate surface is from { orientation beyond the X-ray diffraction intensity I (200) of 200} face and the Cube orientation is promptly from { the X-ray diffraction intensity I (220) of 220} face.And, can obtain than (X-ray diffraction peakedness ratio): I (200)/I (220) by these X-ray diffraction intensities.

The set of common copper alloy plate is organized as mentioned above, be made of considerable steric factor, but when these component ratios changed, the plastic anisotropy of sheet material just changes, and thermotolerance also changes.And, wherein, especially be controlled at proper range by orientation density [also claiming D (Cube)] and the specific crystal orientation density beyond it with the Cube orientation, can improve thermotolerance.

Therefore, in the present invention, the Cube orientation on plate surface is promptly from { orientation beyond the X-ray diffraction intensity I (200) of 200} face and the Cube orientation is promptly from { ratio of the X-ray diffraction intensity I (220) of 220} face: I (200)/I (220) below 0.3, is preferably below 0.25.

Thus, as mentioned above, the prosperity in control Cube orientation, and the prosperity of the specific crystal orientation beyond the reinforcement Cube orientation can strengthen anisotropy, can obtain excellent thermotolerance.And, be the composition of the Cu-Fe-P class copper alloy plate below 0.5% even utilize the content of Fe to lower in fact, high strength and excellent thermotolerance also can get both.

Relative with it, be 0.3 at I (200)/I (220), stricter be to surpass under 0.25 the situation, identical with patent documentation 2 etc. as mentioned above, the prosperity of Cube orientation suppresses the prosperity of the specific crystal orientation beyond the Cube orientation, suppresses anisotropy.Therefore, lowering in fact at the content of Fe is in the composition of the Cu-Fe-P class copper alloy plate below 0.5%, and high strength and excellent thermotolerance can not get both.

(one-tenth of copper alloy plate is grouped into)

For this essentially consist, also can be for further containing a kind of or two kinds mode among Zn, the Sn with following ranges.In addition, other selectivity are added elements and impurity element and are also allowed in the scope that does not hinder these characteristics and contain.In addition, the expression % of the content of alloying element and impurity element all is the meaning of quality %.

(Fe)

Fe separates out as Fe or Fe base intermetallic compound, is intensity and the stable on heating principal element that improves copper alloy.Fe contain quantity not sufficient 0.01% time, according to creating conditions, the growing amount of above-mentioned precipitation particles is few, though satisfy the raising of electric conductivity, is helpless to intensity and improves, intensity and thermotolerance deficiency.On the other hand, when the content of Fe surpasses 0.50%, as above-mentioned prior art, electric conductivity and plating Ag reduction.Therefore, in the time the amount of separating out of above-mentioned precipitation particles must being increased, cause growth, thickization of precipitation particles on the contrary in order to force to increase electric conductivity.Therefore, reductions such as intensity and thermotolerance, punch ram.Thereby the content of Fe is 0.01～0.50% relatively lower scope.

(P)

P forms compound with Fe except that having desoxydatoin, for improving the intensity and the stable on heating principal element of copper alloy.P contain quantity not sufficient 0.01% time, according to creating conditions,, therefore can not obtain desired intensity because separating out of compound is insufficient.On the other hand, when the content of P surpassed 0.15%, not only electric conductivity reduced, and thermotolerance, and hot workability, punch ram etc. also reduce.Therefore, the content of P is 0.01～0.15% scope.

(Zn)

Zn improves the heat-resisting separability of soldering necessary, copper alloy such as lead frame and plating Sn.Under the situation that contains quantity not sufficient 0.005% of Zn, can not obtain desired effects.On the other hand, when surpassing 3.0%, not only soldering soakage reduces, and electric conductivity also reduces greatly.Therefore, make the balance (consideration balance) of the heat-resisting separability of electric conductivity that content that its selectivity contains Zn sometimes requires according to purposes and soldering and plating Sn, in 0.005～3.0% scope, select.

(Sn)

(Mn, Mg, Ca amount)

(Zr, Ag, Cr, Cd, Be, Ti, Co, Ni, Au, Pt amount)

(creating conditions)

Below, to be used to make the copper alloy plate tissue become the invention described above regulation tissue, preferably create conditions and describe.Copper alloy plate of the present invention except that the tissue that is used to make the present invention regulation of having controlled above-mentioned set tissue, the preferred condition such as last cold rolling condition, do not need the earth to change common manufacturing process self, can utilize the operation manufacturing identical with ordinary method.

That is, at first, cast being adjusted into the copper alloy solution that above-mentioned preferred one-tenth is grouped into.And, ingot casting carried out building up by welding after, heat or the thermal treatment that homogenizes, carry out hot rolling afterwards, the plate after the hot rolling is carried out water-cooled.This hot rolling can be common condition.

(cold rolling at last)

For make Cu-Fe-P class copper alloy plate surface from the X-ray diffraction intensity I (200) of (200) face with from the ratio of the X-ray diffraction intensity I (220) of (220) face: I (200)/I (220) is below 0.3, roll speed during the needs increasing is at last cold rolling, perhaps, improve the hardness (Shore hardness) of last roll in cold rolling.That is, selection uses or preferably combination makes with the following method: the roll speed at last cold rolling is increased to more than the 200m/min, perhaps, the hardness (Shore hardness) of the roll at last cold rolling is brought up to 60Hs with first-class method.

Thus, in the poor Cu-Fe-P class of Fe of the present invention copper alloy plate, suppress the prosperity in Cube orientation, and the prosperity of the specific crystal orientation beyond the Reinforced Cu be orientation, strengthen anisotropy, above-mentioned X-ray diffraction intensity ratio: I (200)/I (220) can obtain excellent thermotolerance for below 0.3.

On the other hand, roll speed in the end cold rolling is too small, roll hardness is crossed when hanging down, in the poor Cu-Fe-P class of Fe of the present invention copper alloy plate, and the especially prosperity in Cube orientation, the prosperity of Cube orientation specific crystal orientation in addition can be suppressed, anisotropy can be suppressed.Therefore, above-mentioned X-ray diffraction intensity ratio: I (200)/I (220) can not be for below 0.3.

In addition, in order to improve the punch ram of above-mentioned drawing processing, can strengthen last importing dependent variable in cold rolling.Promptly, select use or preferably combination to make with the following method: cold rolling roller diameter makes the path roll of not enough Φ 80mm at last, perhaps, making the minimum draft (cold rolling rate, working modulus) of each mill train is more than 20%, perhaps, making roll length (roll width) is that 500mm is with first-class method.

Last cold rolling mill train number is avoided very few and too much mill train number, preferably carries out with 3～4 times common mill train numbers.In addition, the draft of each mill train need not to surpass 50%, and each draft of each mill train is considered former thickness of slab, the final thickness of slab after cold rolling, mill train number, this maximum depression rate and determined.

(annealing at last)

(embodiment 2)

Below, embodiments of the invention are described.Roll speed and roll hardness (Shore hardness) during change is at last cold rolling, the above-mentioned X-ray diffraction intensity that has various plates surface with manufacturing compares: the copper alloy thin plate of I (200)/I (220).And, utilize the characteristic such as tensile strength, hardness, electric conductivity, shear surface rate of these each copper alloy thin plate and with the hardness reduction amount evaluation thermotolerance after the annealing in 500 ℃, 1 minute.These results of table 2 expression.

[table 2]

* in the content of each element was represented ,-expression was measured below the boundary,

* the periodic annealing conditions of hardness reduction measurement is 500 ℃ * 1 minute.

Particularly, the copper alloy that each chemical ingredients shown in the table 2 is formed after the melting, does not utilize semicontinuous casting method caststeel ingot respectively in being in the mood for stove, obtain the ingot casting of thickness 70mm * width 200mm * length 500mm.With each ingot casting carry out building up by welding and the heating after, carry out hot rolling with 950 ℃ temperature, make the plate of thickness 16mm, from the temperature more than 750 ℃ at quenching-in water.Then, remove descaling after, carry out once cold rolling (in roll).After this plate carried out building up by welding, carry out the limit and enter the process annealing limit and carry out cold rolling cold rolling at last of 4 mill traines, then, anneal at last, obtain the copper alloy plate of the thickness 0.15mm of corresponding lead frame thin plateization with 350 ℃, 20 seconds cold condition.

Table 2 is represented the last cold rolling roll speed and the hardness (Shore hardness) of roll respectively.In addition, the last cold rolling middle roller diameter that uses is 25% as the minimum draft of 60mm, each mill train.

In addition, it all is Cu that the rest part of each copper alloy shown in the table 2 except that above-mentioned amount of element formed, as other impurity element, the content of Hf, Th, Li, Na, K, Sr, Pd, W, S, Si, C, Nb, Al, V, Y, Mo, Pb, In, Ga, Ge, As, Sb, Bi, Te, B, norium comprises the element of table 2 record, in all totals of these elements, be below the 0.1 quality %.

As mentioned above, to the copper alloy plate that obtains, each example all cuts sample from copper alloy plate, and characteristics such as the set tissue of each sample, tensile strength, hardness, electric conductivity, thermotolerance are evaluated.Table 2 is represented these results respectively.

(mensuration of set tissue)

To the copper alloy plate sample, utilize common X-ray diffraction device, on target, use Co, under the condition of tube voltage 50kV, tube current 200mA, 2 °/min of sweep velocity, 0.02 ° of width of sampling, 30 °～115 ° of measurement ranges (2 θ), the X-ray diffraction intensity I (200) of oneself (200) face on assay plate surface and the X-ray diffraction intensity I (220) of oneself (220) face obtain these X-ray diffraction intensities ratios: I (200)/I (220).Measure at two positions, I (200)/I (220) is their mean value.

(measurement of hardness)

The measurement of hardness of copper alloy plate sample is as follows: utilize micro Vickers, add the load of 0.5kg, carry out at four positions, hardness is their mean value.

(electric conductivity measuring)

(thermotolerance)

In addition, the hardness reduction degree that causes of the thermotolerance utilization of each sample annealing is evaluated.The mensuration of hardness is following carries out: from finish last cold rolling and last stress relief annealed finished product copper alloy plate and annealed with 500 ℃, 1 minute after carry out on the plate of water-cooled, cut the micro Vickers (trade(brand)name: " micro-hardness tester ") of the smart machine of test film (width 10mm * length 10mm) Yong Song swamp society system respectively randomly, add the load of 0.5kg.

Show that by table 2 copper alloy in the present invention forms is to make in the also preferred condition of the manufacture method such as hardness of the in the end cold rolling roll speed of example 1～14, roll.Therefore, the X-ray diffraction intensity I (200) of (200) face certainly on example 1～14 its Cu-Fe-P class copper alloy plate surface and the ratio of the X-ray diffraction intensity I (220) of (220) face certainly: I (200)/I (220) is below 0.3.

This result is, example 1～14 is for tensile strength is more than the 500MPa, hardness is the high strength more than the 150Hv, and having with the hardness reduction amount after the annealing in 500 ℃, 1 minute is the thermotolerance of the excellence below the 30Hv.

Relative with it, though comparative example 15～17 is formed interior copper alloy for the present invention,, last cold rolling roll speed hardness too small or roll is low excessively.Therefore, comparative example 15～17 its above-mentioned X-ray diffraction intensity ratios: I (200)/I (220) substantially exceeds the upper limit 0.3.This result is, strength criterion reduces, and also surpasses 50Hv with the hardness reduction amount after the annealing in 500 ℃, 1 minute, and thermotolerance is significantly inferior.

The content of its Fe of copper alloy of comparative example 18 is 0.005% o'clock, is lower than lower limit 0.01%.On the other hand, make in the also preferred condition of the manufacture method such as hardness of in the end cold rolling roll speed, roll.Therefore, though above-mentioned X-ray diffraction intensity ratio: I (200)/I (220) is below 0.3, and this result is, strength criterion reduces, and also surpasses 40Hv with the hardness reduction amount after the annealing in 500 ℃, 1 minute, and thermotolerance is significantly inferior.

Make in the preferred conditions of manufacture method such as the content of its Fe of copper alloy of comparative example 19 is 0.55% o'clock, exceeds the upper limit 5.0%, and is in the end cold rolling.Therefore, above-mentioned X-ray diffraction intensity ratio: I (200)/I (220) is below 0.3, and thermotolerance and electric conductivity are significantly low.

Make in the preferred conditions of manufacture method such as the content of its P of copper alloy of comparative example 20 is 0.005% o'clock, is lower than lower limit 0.01%, and is in the end cold rolling.Therefore, though above-mentioned X-ray diffraction intensity ratio: I (200)/I (220) is below 0.3, and strength criterion reduces, and also surpasses 40Hv with the hardness reduction amount after the annealing in 500 ℃, 1 minute, and thermotolerance is significantly inferior.

The content of its P of copper alloy of comparative example 21 is 0.17% o'clock, exceeds the upper limit 0.15%, therefore, in hot rolling, cracks in the plate end.But owing to make in the end cold rolling etc. the preferred condition of manufacture method, therefore, though above-mentioned X-ray diffraction intensity ratio: I (200)/I (220) is below 0.3, and thermotolerance and electric conductivity are significantly low.

Can confirm following meaning by above result: the one-tenth that is used on the thermotolerance also excellent copper alloy plate of the present invention is grouped into, above-mentioned X-ray diffraction intensity ratio: the critical meaning of I (200)/I (220) and be used to obtain the meaning of preferably creating conditions of this tissue.

(3)

(mensuration of the orientation distribution density in B orientation)

The mensuration of the orientation distribution density in the Brass orientation of Cu-Fe-P class copper alloy plate of the present invention (B orientation) is according to measuring as the crystal orientation analytic method of EBSP (ElectronBackscatter Diffraction Pattern) with the rear electron diffraction at random of electric field radioactive scanning electronic microscope FESEM (Field EmissionScanning Electron Microscope).

In the present invention, when the set in the Brass orientation of regulation plate is organized, according to the reason of stipulating with the mensuration of the crystal orientation analytic method of above-mentioned EBSP be: in order to improve the adaptation of oxide film, the tissue in the more small zone of plate (plate surface) (set tissue) exerts an influence.In the crystal orientation analytic method with above-mentioned EBSP, quantification is organized in the set in zone that can this is small.

Relative with it, in order to gather organization prescribed or mensuration, in general X-ray diffraction (X-ray diffraction intensity etc.), compare with crystal orientation analytic method with above-mentioned EBSP, can measure the tissue (set tissue) in bigger zone.Therefore, the correct tissue in the above-mentioned more small zone of assay plate (set tissue).

In fact, after personnel measure and compare according to the present invention, even also differ widely each other according to the orientation distribution density value in the B orientation of measuring with the crystal orientation analytic method of above-mentioned EBSP and the orientation identical plate of distribution density value in the B orientation that utilizes X-ray diffraction to measure.Therefore, in the different a plurality of plates comparison each other of the orientation in B orientation distribution density, though in the trend (big trend) of the extremely big or extremely little this group of integral body of the orientation in B orientation distribution density, this two measuring methods unanimity, but in the order of the orientation distribution density value in the B orientation of each plate of measuring, two measuring methods differ widely.Therefore, as a result of, on measuring method each other, there is not interchangeability (dependency).

In other words, as follows by this fact meaning also of the present invention as can be known: the sex situation of driving fit of oxidated film is organized in the set in the more small zone of plate, and the mensuration of the crystal orientation analytic method of above-mentioned EBSP is used in utilization, stipulates the Brass orientation set tissue in the zone that this is small.

(the orientation distribution density measuring method in B orientation)

The rear electron diffraction pattern at random (Kikuchi pattern) that this crystal orientation analytic method produces when specimen surface is tiltedly shone the electronics line is resolved crystal orientation.And this method also is known as high de-agglomeration energy crystal orientation method of analysis (FESEM/EBSP method) even crystal orientations such as diamond thin and copper alloy are resolved.Identical with the present invention, the example of carrying out the crystal orientation parsing of copper alloy with this method also is disclosed Japan and openly speciallys permit communique: 2005-29857 number, Japan and openly specially permit communique: 2005-139501 number etc.

The parsing order of this crystal orientation analytic method is divided into zones such as sexangle with the mensuration area region of determined material earlier usually, to each zone of distinguishing, by the reflection electronic acquisition Kikuchi pattern (B orientation reflection) of the electronics line that is incident in specimen surface.At this moment, with the electronics line with two-dimensional scan at specimen surface, as long as measure the crystal orientation of every regulation pitch, the orientation that can measure specimen surface distributes.

Below, resolve the above-mentioned Kikuchi pattern that obtains, as can be known the crystal orientation of electronics line incoming position.That is, the Kikuchi pattern that obtains and the data of known crystalline texture are compared, obtain the crystal orientation on its measuring point.Equally, obtain the crystal orientation of the adjacent measuring point of its measuring point, these crystalline azimuth differencees adjacent one another are ± 15 ° with interior (from crystal plane, ± 15 ° with interior displacement) crystal orientation belong to the crystal orientation of same crystal plane as (regarding as), in addition, crystalline azimuth difference both sides surpasses under ± 15 ° the situation, is the grain boundary with its interval (limit that both sides' sexangle joins etc.).So, just obtain the distribution of the grain boundary of specimen surface.

More specifically, cut the test film that structure observation is used, after carrying out mechanical mill and polishing grinding, carry out electrolytic polishing, to adjust the surface from the copper alloy plate of making.To the test film that so obtains, use the EBSP of the FESEM of NEC society system for example and TSL society system to measure, resolution system OTM (Orientation Imaglng Macrograph), and parsing software (software name " OIMAnalysis ") with homologous ray, judge each crystal grain as the orientation density in the Brass orientation of object (from desirable orientation, in 15 °) could, and obtain the Brass orientation density of measuring in the visual field.

This mensuration field range is small (small) zone of 500 μ m * 500 μ m degree, even compare with the measurement range of X-ray diffraction, also is remarkable small zone.Therefore, the orientation density measurement of tissue in more small zone of plate that influences the adaptation of oxide film is compared with the orientation density measurement of X-ray diffraction, as mentioned above, can be carried out more in detail and accurately.

In addition, change along the thickness of slab direction, therefore, preferably average arbitrarily and obtain in thickness of slab direction arbitrfary point because their orientation distributes.But, under the situation of the copper alloy plate that is used for semiconductor material such as lead frame, because thickness of slab is the thin plate of 0.1～0.4mm degree, therefore, even also can evaluate with the value of intact measurement of plate thickness.

(meaning of orientation distribution density)

In the present invention, as mentioned above,, and particular orientation is adjusted the prosperity of its rolling set tissue for the adaptation of the high strength of the poor Cu-Fe-P class of the Fe that gets both copper alloy plate and excellent oxide film.

Therefore, in the present invention, increase the orientation density in (raising) Brass orientation (B orientation), the mensuration of the crystal orientation analytic method by adopting above-mentioned FESEM/EBSP makes the set tissue more than 25%.But as prerequisite, in the present invention, these crystalline azimuth differencees adjacent one another are are regarded the crystal orientation that belongs to same crystal plane as at ± 15 ° of crystal orientations with interior (from crystal plane, ± 15 ° with interior displacement).

In the copper alloy plate that the Cu-Fe-P class with Fe content few (below 0.5%) is formed, the orientation distribution density in B orientation is bigger to the adaptation influence of oxide film.The orientation distribution density in B orientation is big more, and rolling set is organized all the more and reached, and intensity is high more, and can improve the adaptation of oxide film.

Relative with it, in the Brass orientation during the above-mentioned orientation distribution density less than 25% in (B orientation), the rolling set of the poor Cu-Fe-P class of Fe copper alloy plate organize undeveloped and intensity low, and do not improve the adaptation of oxide film.

(average crystal grain diameter)

In the present invention, as to above-mentioned set Microstructure Control and be used to bring into play the precondition that the effect of self is organized in above-mentioned set, the average crystal grain diameter that makes the copper alloy plate tissue is in the measured value of the crystal orientation analytic method that adopts above-mentioned FESEM/EBSP: be below the 6.0 μ m.This average crystal grain diameter is fine to be turned to below the 6.0 μ m by making, and can improve the adaptation of oxide film, in addition, to above-mentioned set Microstructure Control, and above-mentioned set organize the adaptation of the oxide film of self to improve the effect performance easily.On the other hand, surpass 6.0 μ m and under the situation of thickization at this average crystal grain diameter, to above-mentioned set Microstructure Control, and above-mentioned set organize self effect performance difficulty.

This average crystal grain diameter can be measured in the process that the orientation distribution density in the B orientation of the crystal orientation analytic method that adopts FESEM/EBSP is measured as mentioned above.

(one-tenth of copper alloy plate is grouped into)

In the present invention, use etc. as semiconductor lead frame, with tensile strength be more than the 500MPa, hardness is more than the 150Hv, electric conductivity is that high strength and excellent oxide film adaptation more than the 50%LACS realizes in the lump.Therefore, as Cu-Fe-P class copper alloy plate, it basic composition is: in quality %, the content of Fe is that the content of 0.01～0.50% scope, above-mentioned P is 0.01～0.15% scope, and rest part is by Cu and can not keep away impurity and constitute.

(Fe)

(P)

(Zn)

(Sn)

(Mn, Mg, Ca amount)

(Zr, Ag, Cr, Cd, Be, Ti, Co, Ni, Au, Pt amount)

(creating conditions)

(cold rolling at last)

The last cold rolling ordinary method of also utilizing.But, for drawing is that intensity in the thermal treatment (stress relieving) etc. behind the lead frame reduces less and thermotolerance is improved, preferably strengthen last roll speed in cold rolling, perhaps, improve the hardness (Shore hardness) of last roll in cold rolling.That is, selection uses or preferably combination makes with the following method: the roll speed at last cold rolling is increased to more than the 200m/min, perhaps, the hardness (Shore hardness) of the roll at last cold rolling is brought up to 60Hs with first-class method.

(annealing at last)

Among the present invention, in the end cold rolling after, preferably in successional heat treatment furnace, carry out with cryogenic last annealing.Last annealing conditions in this successional heat treatment furnace is preferably with 100～400 ℃, 0.2～300 minute cold condition.In the manufacture method of the common copper alloy plate that is used for lead frame, except that the annealing that is used to reduce intensity, be used to eliminate stress (350 ℃ * 20 seconds degree), in the end cold rolling after, do not anneal at last.But, in the present invention,, in addition,, can suppress this intensity and reduce by last annealed low temperatureization according to above-mentioned cold rolling condition.And, by annealing at last, improve punch ram with low temperature.

(the set tissue in the annealing, average crystal grain diameter control at last)

In addition,, can become set tissue, the average crystal grain diameter of the invention described above regulation, can improve intensity, can improve the adaptation of oxide film by in successional heat treatment furnace, carrying out this last annealing.That is, in successional heat treatment furnace, the tension force and the threading speed of the plate load in the time of can controlling sheet material and wear stove, thus, the orientation distribution density that can make Brass orientation (B orientation) is that the rolling set tissue more than 25% is flourishing.In addition, can turn to below the 6.0 μ m average crystal grain diameter is fine.The tension force of the plate load the when sheet material in the successional heat treatment furnace is worn stove and threading speed are bigger to the orientation distribution density and the average crystal grain diameter influence in Brass orientation (B orientation).

In order to make the set tissue and the average crystal grain diameter of this present invention regulation, when the sheet material in the last annealing that successional heat treatment furnace carries out is worn stove, at 0.1～8kg/mm ²Scope in apply tension force, and threading speed is controlled in the scope of 10～100m/min.Either party or both sides break away under the situation of this scope in tension force when sheet material is worn stove and the threading speed, probably can not become the set tissue and the average crystal grain diameter of the present invention's regulation.

(embodiment 3)

Below, embodiments of the invention are described.Tension force and threading speed when changing sheet material in the last annealing that successional heat treatment furnace carries out and wearing stove have the orientation distribution density in various Brass orientation (B orientation), the copper alloy thin plate of average crystal grain diameter with manufacturing.And, to characteristics such as the tensile strength of these each copper alloy thin plate, hardness, electric conductivity, and the adaptation (exfoliation temperature of oxide scale film) of oxide scale film evaluate.These results of table 3 expression.

[table 3]

* in the content of each element was represented ,-expression was measured below the boundary.

Particularly, the copper alloy that each chemical ingredients shown in the table 3 is formed after the melting, does not utilize semicontinuous casting method casting steel ingot respectively in being in the mood for stove, obtain the ingot casting of thickness 70mm * width 200mm * length 500mm.With each ingot casting carry out building up by welding and the heating after, carry out hot rolling with 950 ℃ temperature, make the plate of thickness 16mm, from the temperature more than 750 ℃ at quenching-in water.Then, remove descaling after, carry out once cold rolling (in roll).After this plate carried out building up by welding, carry out the limit and enter the process annealing limit and carry out cold rolling cold rolling at last of 4 mill traines, then, anneal at last for 450 ℃, obtain the copper alloy plate of the thickness 0.15mm of corresponding lead frame thin plateization with the atmosphere temperature degree of stove.

Last cold rolling roll speed is 300m/min, and the hardness of roll (Shore hardness) is 90Hs, uses roller diameter to be Φ 60mm, and the minimum draft of each mill train is 10%.

Each tension force (kgf/mm when sheet material in the last annealing that the successional heat treatment furnace of table 3 expression carries out is worn stove ²) and each threading speed (m/min).

In addition, it all is Cu that the rest part of each copper alloy shown in the table 3 except that above-mentioned amount of element formed, as other impurity element, the content of Hf, Th, Li, Na, K, Sr, Pd, W, S, Si, C, Nb, Al, V, Y, Mo, Pb, In, Ga, Ge, As, Sb, Bi, Te, B, norium comprises the element of table 3 record, in all totals of these elements, be below the 0.1 quality %.

To the above-mentioned copper alloy plate that obtains like that, each example all cuts sample from copper alloy plate, and the characteristics such as adaptation of the set tissue of each sample, tensile strength, hardness, electric conductivity, oxide scale film are evaluated.Table 3 is represented these results respectively.

(mensuration of set tissue)

Cut the test film that structure observation is used from the above-mentioned copper alloy plate that obtains, after carrying out mechanical mill and polishing and grinding, carry out electrolytic polishing and adjust the surface.Each test film that obtains is measured with aforesaid method,,, measured the orientation distribution density in Brass orientation (B orientation) with the interval of 1 μ m to the zone of 500 μ m * 500 μ m.

Measure and resolve as mentioned above, carry out with the parsing software of EBSP mensuration, resolution system and the homologous ray of the FESEM of Jeol Ltd.'s system and TSL society system.

(measurement of hardness)

As mentioned above, cut the test film of 10 * 10mm from the copper alloy plate that obtains, the micro Vickers (trade(brand)name: " micro-hardness tester ") of the smart machine of Yong Song swamp society system adds the load of 0.5kg, measures at four positions, and hardness is their mean value.

(electric conductivity measuring)

(oxide film adaptation)

In addition, the oxide film adaptation of each sample is evaluated with the critical temperature that oxide film is peeled off by the tape stripping test.The tape stripping test is following to be carried out: as mentioned above, from cut the test film of 10 * 30mm from the copper alloy plate that obtains, in atmosphere with after the specified temperature heating 5 minutes, commercially available tape (trade(brand)name: Sumitomo スリ-エ system glue connects tape) is posted in the test film surface that oxide film generates, peels off then.At this moment, when making the Heating temperature rising change to 10 ℃ of scales, obtaining the minimum temperature of peeling off generation of oxide film, is the oxide film exfoliation temperature with this temperature.

Show by table 3, the copper alloy of the present invention in forming be the sheet material of example 1～14 in the last annealing of successional heat treatment furnace when wearing stove tension force and the preferred condition of threading speed in make.Therefore, the orientation distribution density that example 1～14 has a Brass orientation that the said determination method measures is the set tissue more than 25%, can turn to below the 6.0 μ m average crystal grain diameter is fine.

This result is, example 1～14 is for tensile strength is more than the 500MPa, hardness is the high strength more than the 150Hv, and having the oxide film exfoliation temperature is the oxide film adaptation of the excellence more than 350 ℃.Therefore, example 1～14 is as the semi-conductor mother metal, the adaptation height of resin the during assembling of package semiconductor and backing plate, and the reliability height of packing.

Relative with it, though comparative example 15～17 is formed interior copper alloy for the present invention,, either party or the preferred condition of both sides in tension force the when sheet material in the last annealing of disengaging successive heat treatment furnace is worn stove and the threading speed.Therefore, the orientation distribution density less than 25% in the Brass orientation that comparative example 15～17 its said determination methods are measured, and median size also surpasses 6.0 μ m and thickization.This result is, strength criterion reduces, and the oxide film exfoliation temperature is below 330 ℃, and the oxide film adaptation is significantly inferior.

The content of its Fe of copper alloy of comparative example 18 is 0.007% o'clock, is lower than lower limit 0.01%.Make in tension force when on the other hand, the sheet material in the last annealing of successional heat treatment furnace is worn stove and the preferred condition of threading speed.Therefore, be set tissue more than 25% though have the orientation distribution density in Brass orientation, can turn to below the 6.0 μ m average crystal grain diameter is fine, oxide film adaptation excellence, strength criterion reduces.

The content of its Fe of copper alloy of comparative example 19 is 0.58% o'clock, exceeds the upper limit 5.0%.Make in tension force when on the other hand, the sheet material in the last annealing of successional heat treatment furnace is worn stove and the preferred condition of threading speed.Therefore, be set tissue more than 25% though have the orientation distribution density in Brass orientation, can turn to below the 6.0 μ m average crystal grain diameter is fine, oxide film adaptation excellence, electric conductivity significantly reduces.

The content of its P of copper alloy of comparative example 20 is 0.008% o'clock, is lower than lower limit 0.01%.Make in tension force when on the other hand, the sheet material in the last annealing of successional heat treatment furnace is worn stove and the preferred condition of threading speed.Therefore, be set tissue more than 25% though have the orientation distribution density in Brass orientation, can turn to below the 6.0 μ m average crystal grain diameter is fine, oxide film adaptation excellence, strength criterion reduces.

The content of its P of copper alloy of comparative example 21 is 0.16% o'clock, exceeds the upper limit 0.15%, therefore, in hot rolling, cracks in the plate end.Make in tension force when on the other hand, the sheet material in the last annealing of successional heat treatment furnace is worn stove and the preferred condition of threading speed.Therefore, be set tissue more than 25% though have the orientation distribution density in Brass orientation, can turn to below the 6.0 μ m average crystal grain diameter is fine, oxide film adaptation excellence, electric conductivity significantly reduces.

Can confirm following meaning by above result: be used for make thermotolerance on its high strength also the one-tenth of excellent copper alloy plate of the present invention be grouped into, gather the critical meaning of organization prescribed and be used to obtain the meaning of preferably creating conditions of this tissue.

Industrial utilizability

As mentioned above, according to the present invention, can be provided in and make the also Cu-Fe-P class copper alloy plate of excellent and (having both) these characteristics that get both of punch press stampability on its high strength.

In addition, according to the present invention, can be provided in and make the also Cu-Fe-P class copper alloy plate of excellent and (having both) these characteristics that get both of heat resistance on its high strength.

In addition, according to the present invention, can be provided in and make the also Cu-Fe-P class copper alloy plate of excellent and (having both) these characteristics that get both of oxide-film adaptation on its high strength. This result is, the resin the when assembling of package semiconductor can be provided and the adaptation height of backing plate, the high semiconductor mother metal of reliability of packing.

These results are applicable to following purposes: use as miniaturization and light-weighted electrical/electronic part, except semiconductor device with the lead frame, also be applicable to the purposes that requires high strength and strict bendability of lead frame, binding post, terminal, switch, relay etc. and require stable on heating purposes or be applicable to the purposes of the reliability that requires oxide-film adaptation=packing.

Claims

1. copper alloy sheets for electrical/electronic part, it is characterized in that, contain Fe:0.01～0.50%, P:0.01～0.15% in quality %, wherein, by formation make the plate surface from { half breadth of the X-ray diffraction intensity peak value of 311} face is a tissue more than 0.015 divided by the value of its peak height gained, improves punch ram thus.

2. copper alloy sheets for electrical/electronic part as claimed in claim 1 is characterized in that, described copper alloy plate also contains Sn:0.005～5.0% and/or Zn:0.005～3.0% in quality %.

3. copper alloy sheets for electrical/electronic part as claimed in claim 1 or 2 is characterized in that, the tensile strength of described copper alloy plate is more than the 500MPa, and hardness is more than the 150Hv.

4. copper alloy sheets for electrical/electronic part as claimed in claim 1 or 2 is characterized in that, described copper alloy plate also contains the element that is made of more than one the group that is selected from following A group～D group in quality %,

The A group:

Add up to 0.0001～1.0% Mn, Mg, one or two or more kinds among the Ca;

The B group:

Add up to one or two or more kinds among 0.001～1.0% Zr, Ag, Cr, Cd, Be, Ti, Co, Ni, Au, the Pt;

The C group:

Contain and add up to 0.0001～1.0% Mn, Mg, one or two or more kinds among the Ca, with add up among 0.001～1.0% Zr, Ag, Cr, Cd, Be, Ti, Co, Ni, Au, the Pt one or two or more kinds, and the total content of the above-mentioned element that contains is below 1.0%;

The D group:

The content of Hf, Th, Li, Na, K, Sr, Pd, W, S, Si, C, Nb, Al, V, Y, Mo, Pb, In, Ga, Ge, As, Sb, Bi, Te, B, norium is counted below 0.1% with all totals of these elements.